Fuse switch



J. L. TURNER FUSE SWITCH Filed May 4, 1950 FIGZ.

Patented Dec. 26, 1950 FUSE SWITCH John L. Turner, East St. Louis, 111., assignor to W. N. Matthews Corporation, St. Louis, Mo., a corporation of Missouri Application May 4, 1950, Serial No. 159,968

6 Claims. 1

This invention relates to fuse switches and more particularly to such switches wherein a fuse link is held under tension and which are adapted for out-door service on electrical power line poles or the like.

The object of the invention is the provision of an improved fuse switch of the class described which is of economical construction and which operates reliably to separate the terminals of a fuse link upon blowing of the link, even under severe icing conditions.

In general, a fuse switch of this invention comprises an insulator or insulators such as may be mounted vertically or in angle underhung position on a cross arm on a power line pole. A terminal adapted for attachment of one lead of a conventional fuse link is mounted on the insulator. Also mounted on the insulator is an electrically conductive resilient rod having a portion coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, and another portion thereof forming a cantilever arm extending outward from one end of the spring generally transverse to the direction of length of the spring. The spring has its other end secured to the insulator spaced from the terminal with the arm extending outward away from the insulator. The arm is adapted for attachment of the other lead of the fuse link to its free end when its free end is forced against the bias of the spring toward the terminal, so as to hold the fuse link under tension between the terminal and the free end of the arm. The spring is secured to the insulator in such position that when the free end of the arm is forced toward the terminal, the convolutions of the spring are forced together on one side of the spring axis and forced apart on the other. Other features willbe in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In theaccompanying drawing, in which one of various possible embodiments of the invention is illustrated,

Fig. 1 is a view in elevation of a fuse switch of this invention as it is mounted on a crossarm holding a fuse link under tension;

Fig. 2 is a plan View of Fig. 1 as viewed on the line 2-2 of Fig- 1;

Fig. 3 is a fragmentary detail as viewed on the line 33 of Fig. 1; and

Fig. 4 is a section taken on line 3-4 of Fig. 1.

Similar reference characters indicate corresponding parts through the several views of the drawing.

Referring to the drawing, a fuse switch of this invention is shown to comprise an elongate insulator i which is equipped with a bracket 3 for mounting the insulator in angle underhung position on a cross-arm on a power line pole, or which can be furnished with a bracket for mounting in vertical position. At the upper end of the insulator is a terminal 5 for attachment of one lead of a fuse link 1. An electrically conductive spring terminal 9 extends outward from the lower end of the insulator and is adapted to be flexed against its inherent bias toward the terminal 5 for attachment of the other lead of the fuse link I to its free end for holding the fuse link under tension. The invention resides particularly in the construction of the spring terminal 9 and its attachment to the end of the insulator.

The terminal 5 comprises a length of electrically conductive resilient rod (a copper alloy rod, for example) bent to form a loop ll shaped like an inverted U with arms I 3 extending at right angles to the plane of the loop from the lower ends of the legs of the loop. These arms are bent toward one another to meet at I5 and have straight portions ll engaged side-by-side extending to the free end of the terminal 5 where the arms have portions is bent back and flared outward to provide two clip portions 20 in either of which may be wedged the flexible lead 2! extending from one end of a fuse link tube 23. The outer ends of the arm portions I! are held together by a cap 25. On one leg of the loop is a conventional bolt connector 21 for attaching a conductor (not shown) to the terminal. The terminal is clamped to the upper end of the insulator by means of a clamp member 29 bolted to the insulator as indicted at 3| with the legs of the loop H held in the clamp, with the loop extending upward above the upper end of the insulator, and with the arms is extendin transversely outward from the insulator.

The spring terminal 9 is made of a length of electrically conductive resilient rod (copper alloy rod, for example) having a portion thereof coiled about an axis into a helically convoluted spring 33, the convolutions of which are axially displaced, (i. e., the spring is not a flat spiral spring) and another portion thereof forming a cantilever spring.

arm extending outward from one end of the spring in a direction generally transverse to the direction of the length of'the spring and in a plane including, or at least approximately including, the axis of the spring. For example, when the spring is unstressed, the arm may extend approximately at right angles to the spring axis. A portion of the rod is formed into a loop 3? extending outward from the other end of the spring generally parallel to and spaced from the spring axis.

The arm 35 has a portion 39 at its free endbent back and flared outward to provide a clip dl' in which may be wedged the flexible-lead itextending from the other end of the fuse link tube 23. A cap 55 is fitted on the doubled end of the arm. The arm may be bent as indicated atli to provide a wide throat 49 for facilitating entry of the lead &5 in the clip il. The loop 31 is of U shape.

A generally straight reach 5! of the rod extending at'r-ight angles to the plane of the loop from the end of one of its legs leadsinto the end of the An end reach-530i the rod extends from the-'endoi the other leg of the loop alongside the reach 5 5.

An angle bracket 55 has one leg 5? bolted to the'lower end of the insulator'as indicated at 59 with its other leg'fi'i extending generally transverselyoutwardfrom the lower end of the insulator on the same side of the insulator as the terminal-5. The spring 33 is secured at its looped end to'the'l'eg 6i of the bracket with its axis positioned at least approximately in the vertical plane includin-gthe terminal 5 and with'the arm 35 extending outward away from the insulator at least approximately in thisplane. As shown, the spring is secured to the leg E l with its axis generally parallel to the axis of the "insulator and with the arm 35 extending outward from the upperend of the spring, the reaches 51 and 53 being clamped againstthe bottom of the leg 6| by means of-a clamping member 63'bolted to the leg M as indicated at Ed. On one leg of the loop 31 is a conventional bolt connector El for attaching a conductor (not shown) to the loop 3 Onthe ends of the-fuselinkleads? l and 53 are heads ll andld and rings "l5 and Ti, respectively.

Thefuse link is applied'byraising thelink with a hook stick, the hook being inserted in ring it,

wedging the lead l? in clip '51, lifting the link after the lead is wedged in the clip to'foreethe free'end of the-arm sia toward the terminal 5, and then wedging the lead 2i in one or the other of clips it]. The arm 3 5 tends-to spring downward under the bias of the stressed spring which flexes as illustrated in Fig. l to force together or contract the convolutions on the side of its axis toward the insulator and to force apart the cen- "volutionson the side of its axis away from'the insulator, and this holds the link under tension between the heads ll and '13. When the fusible element id of the link blows, the arm 35'springs down and pulls the'lead 33 out of the fuse tube 23 to extinguish the are that may result from the blowing of the element 79.

It will be understood that the spring 53 may be coiled so that, in its unstressed condition, its

axially displacedconvolutions are either in engagement or spaced apart, these types of helical springs being well-known.

An important advantage of securing the spring 3 3 to the insulator in the position illustrated and "described is that spring action of the arm 35 is assured, when the fuse link blows, even under severe'icing conditions, without any necessity for providing an ice shield or the like. Another ad vantage of the invention resides in the provision contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

'I-"claim: 1. A fuse switch comprising an insulator, a terminal mounted on said insulator adapted for attachment of one lead-of a fuse link, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, and another portion thereof forming a cantilever arm extending outward from one-end-ofthe spring, the spring being secured at its other end to the insulator spaced from said terminal with the arm extending outward away from the insulator, said arm being adapted for attachment .of the other lead of the fuse link to its free end when itsfree end is-forced against the bias of the spring towardthe-terminal to hold the fuse link under tension between-the terminal and the free end of the arm, the-spring being secured to the-insulatorw-ith its axis generally in the planein which the arm moves when its free end is forced -'toward the terminal, so that when the free end of the'arm is forced toward t1 e terminal, the convolutionsof the spring are forced together on one side of the spring axis and forced apart on the other.

2. A fuse switch comprising an insulator, a terminal mounted on said insulator adapted for attachment of one-lead of a-fuse link, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically con- Voluted spring, the convolutionsof which are axially displaced, another portion thereof forming a cantilever arm extending outward from one end of the spring in a-direction generally transverse to the direction of length of the spring, and another portion forming a loop extending outward from the otherendof the spring, the spring being secured at its said other end to th insulator spaced from said terminal with the arm extending outward away from the insulaton'said arm being adapted for attachment of the other lead of the fuse link to its free end when its free end is forced against the bias of the spring toward the terminal to hold the fuse link under tension between the terminal and the free end of the arm, the springbeing secured'to the insulator in such position that when the free end of the arm is forced toward the terminal, the convolutions of the 'spring'are forced together on one side of the spring axis and forced apart on the other.

3. A fuse switch comprising an elongate insulator, a terminal extending transverseiy outward from one end of said insulator having a clip at its outer end for attachment of one lead of a fuse link, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, and another portion thereof forming a cantilever arm extending outward from one end of the spring in a direction generally transverse to the direction of length of the spring, the spring being secured at its other end to the other end of the insulator with the arm extending generally transversely outward away from the insulator generally in the plane of the insulator and the terminal, said arm having a clip at its free end for attachment of the other lead of the fuse link when its free end is forced against the bias of th spring toward the terminal to hold the fuse link under tension between the terminal and the free end of the arm, the spring being secured to the insulator in such position that when the free end of the arm is displaced toward the terminal, the convolutions of the spring are forced together on one side of the spring axis and forced apart on the other.

4. A fuse switch comprising an elongate insulator, a terminal extending transversely outward from one end of the insulator on one side of the insulator and having a clip at its outer end for attachment of one lead of a fuse link, a bracket extending transversely outward from the other end of the insulator on said one sid of the insulator, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, and another portion thereof forming a cantilever arm extending outward from one end of the spring generally transverse to the direction of length of the spring, the spring having its other end secured to the bracket with its axis generally parallel to the length of the insulator and with the arm extending transversely outward away from the insulator on said one side of the insulator, said arm having a clip at its free end for attachment of the other lead of the fuse link when the free end of the arm is forced toward the terminal.

5. A fuse switch comprising an elongate insulator, a terminal extending transversely outward from one end of the insulator on on side of the insulator and having a clip at its outer end for attachment of one lead of a fuse link, a bracket extending transversely outward from the other end of the insulator on said one side of the insulator, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, another portion thereof forming a cantilever arm extending outward from one end of the spring generally transverse to the direction of length of the spring, and another portion forming a loop extending outward from the other end of the spring generally parallel to the axis of the spring, the spring having its other end secured to the bracket with its axis generally parallel to the length of the insulator and with the arm extending transversely outward away from the insulator on said one side of the insulator, said arm having a clip at its free end for attachment of the other lead of the fuse link when the free end of the arm is forced toward the terminal.

6. A fuse switch comprising an elongate insulator, a terminal extending transversely outward from one end of the insulator on one side of the insulator and having a clip at its outer end for attachment of one lead of a fuse link, a bracket extending transversely outward from the other end of the insulator on said one side of the insulator, an electrically conductive resilient rod having a portion thereof coiled about an axis into a helically convoluted spring, the convolutions of which are axially displaced, another portion thereof forming a cantilever arm extending outward from one end of the spring generally transverse to the direction of length of the spring, and another portion forming a loop extending outward from the other end of th spring generally parallel to the axis of the spring, the spring having its other end secured to the bracket and extending from the bracket toward the terminal with its axis generally parallel to the length of the insulator and with the arm extending transversely outward away from the insulator on said one side of the insulator, said arm having a clip at its free end for attachment of the other lead of the fus link when the free end of the arm is forced toward the terminal, the loop extending in the opposite direction from the bracket and carrying a connector for attaching a conductor thereto.

JOHN L. TURNER.

No references cited. 

